Php Symfony返回一些字段实体OneToMany

我有一个实体项目和一个域一个域一个域，当我返回项目时，我@Expose（）这个域和一个域一个域一个域一个域一个域都有 所有字段位都有@Expose。在实体位中，我对一些字段有注释@Groups（{“list”}），例如id，当我返回实体项目时，如何对位使用这个注释@Groups（{“list”}）？我需要这个项目的返回计数位，我知道如何找到计数位，比如$count=count（$project->getBit（）->getValues（）），以及这个计数如何添加到返回项目中（$projects，根据某些条件，这是数组项目）

实体：

 class Project
 {
/**
 * @var integer
 *
 * @ORM\Column(name="id", type="integer")
 * @ORM\Id
 * @Expose()
 * @ORM\GeneratedValue(strategy="AUTO")
 */
private $id;

/**
 * @var string
 *
 * @ORM\Column(name="project_name", type="string", length=255, nullable=true)
 * @Expose()
 * @Type("string")
 */
protected $project_name;

/**
 * @ORM\OneToMany(targetEntity="Bit", mappedBy="projectId", cascade={"remove"})
 * @Expose()
 */
protected $bit;

位：

在这个json中，我不需要位中的开发者，只需要位中没有关系的字段

{
"id": 101,
"main_skill": "105",
"type": "fixed_cost",
"name": "fsfefsef",
"markets": [
  "2"
],
"platforms": [
  "2"
],
"speciality": [],
"slug": "105-fsfefsef",
"description": "fsefs",
"duration": "fsef",
"expected_budget": "$ 34.00",
"project_skills": [
  "15"
],
"created": "2015-11-27T12:24:39+0200",
"closed": 0,
"stripped_name": "__105_fsfefsef",
"current_status": "published",
"bit": [
  {
    "id": 501,
    "created": "2015-11-27T12:25:11+0200",
    "developer_id": {
      "id": 82,
      "level": "Senior",
      "main_skill": "Ext JS",
      "skills": [
        "jQuery",
        "Dojo",
        "Akelos",
        "Visual Studio",
        "jenkins",
        "WPF",
        "LMS",
        "Hadoop",
        "gui",
        ".NET",
        "JavaScript",
        "Web",
        "DevOps",
        "Parse",
        "Java EE",
        "Python"
      ],
      "platforms": [],
      "english": "Basic",
      "rate": 6,
      "tags": [
        "tag5",
        "only main skill"
      ],
      "user": [
        {
          "id": 200,
          "first_name": "Twila",
          "last_name": "Leuschke",
          "email": "bulah.wolff@gmail.com",
          "skype": "Crystal Bartoletti",
          "telephone": "1-933-454-0851x97226"
        }
      ],
      "created_at": "2015-11-27T12:19:18+0200",
      "updated_at": "2015-11-27T12:19:37+0200"
    },
    "rate": 4,
    "comment": "fsefsf"
  },

class Bit
{
/**
 * @var integer
 *
 * @ORM\Column(name="id", type="integer")
 * @ORM\Id
 * @ORM\GeneratedValue(strategy="AUTO")
 * @Expose()
 * @Groups({"list"})
 */
private $id;

/**
 * @var datetime $created
 *
 * @Gedmo\Timestampable(on="create")
 * @ORM\Column(type="datetime")
 * @Expose()
 */
private $created;

/**
 * @var datetime $updated
 *
 * @Gedmo\Timestampable(on="update")
 * @ORM\Column(type="datetime")
 */
private $updated;

{
"id": 101,
"main_skill": "105",
"type": "fixed_cost",
"name": "fsfefsef",
"markets": [
  "2"
],
"platforms": [
  "2"
],
"speciality": [],
"slug": "105-fsfefsef",
"description": "fsefs",
"duration": "fsef",
"expected_budget": "$ 34.00",
"project_skills": [
  "15"
],
"created": "2015-11-27T12:24:39+0200",
"closed": 0,
"stripped_name": "__105_fsfefsef",
"current_status": "published",
"bit": [
  {
    "id": 501,
    "created": "2015-11-27T12:25:11+0200",
    "developer_id": {
      "id": 82,
      "level": "Senior",
      "main_skill": "Ext JS",
      "skills": [
        "jQuery",
        "Dojo",
        "Akelos",
        "Visual Studio",
        "jenkins",
        "WPF",
        "LMS",
        "Hadoop",
        "gui",
        ".NET",
        "JavaScript",
        "Web",
        "DevOps",
        "Parse",
        "Java EE",
        "Python"
      ],
      "platforms": [],
      "english": "Basic",
      "rate": 6,
      "tags": [
        "tag5",
        "only main skill"
      ],
      "user": [
        {
          "id": 200,
          "first_name": "Twila",
          "last_name": "Leuschke",
          "email": "bulah.wolff@gmail.com",
          "skype": "Crystal Bartoletti",
          "telephone": "1-933-454-0851x97226"
        }
      ],
      "created_at": "2015-11-27T12:19:18+0200",
      "updated_at": "2015-11-27T12:19:37+0200"
    },
    "rate": 4,
    "comment": "fsefsf"
  },